LIGGGHTS-PFM 24.01 release

Notable Changes

• Added a history option for fix property/atom (enabling time derivatives)
• Added dump_modify option domainfile to disable domain files written by dump custom/vtk
• Added fix move/mesh style rotate/superposable (contributed by G. Holzinger)
• Added optional per-atom heat capacity (use either fix property/global or fix property/atom)
• Added layer- and temperature-dependent specific heat in chemistry model
• Modified chemistry model: per-layer pore-diameter (now property/global vector instead of property/global scalar)
• Fixed chemistry model: sign of reaction heat
• Fixed issue in fix insert/pack/dense with finding nearest insertion position
• Fixed issue in region wedge
• Fixed issues in moving composed regions (union, intersect)
• Fixed potential deadlock in multi-partition simulations
• Fixed deletion of atoms in fix remove, fix couple/cfd/deform, fix couple/cfd/dissolve, fix massflow/mesh, fix massflow/mesh/face
• Fixed issue in restarting fix multisphere in combination with fix massflow/mesh
• Fixed limitation of only one fix massflow/mesh working with fix multisphere

Full Changelog: 23.02...24.01

LIGGGHTS-PFM 23.02 release

Notable Changes

• Added the normal and tangential contact models hertz/lubricated and history/lubricated (contributed by T.M.J. Nijssen)
• Added fix couple/cfd/fluidproperties command to communicate fluid density and (dynamic) viscosity from CFDEMcoupling to LIGGGHTS (contributed by T.M.J. Nijssen)
• Added tutorials demonstrating size segregation effects
• Fixed an issue with restarting of fix massflow/mesh and fix masslow/mesh/face
• Fixed an issue with resetting of equal-style script variables
• Fixed an issue with the distribution of fragments in fix break/particle in parallel runs
• Fixed an issue with the parsing of VTK tetrahedral mesh files
• Fixed an issue with compute pair/gran/local in case of non-contact inter-particle forces (e.g cohesion)
• Fixed an issue with the hybrid atom style in cases where the particle radius was changing during simulation
• Fixed an issue with CFD-DEM data coupling for scalar-global and vector-global types
• Modified the frequency factors and activation energies for low temperature Fe3O4->Fe reactions in fix chem/shrink/core

LIGGGHTS-PFM 21.11 release

Notable Changes

• Added fix cfd/coupling/dissolve command to exchange mass transfer data between LIGGGHTS and CFDEMcoupling and shrink/grow particles accordingly (contributed by T.M.J. Nijssen)
• Added an option to limit reactant consumption in fix chem/shrink/* commands
• Added an option to monitor heat in fix remove command
• Added a direction-based removal algorithm to the delete_atoms command
• Added a tutorial demonstrating size segregation
• Added a test case demonstrating heat conduction between 2 spheres of different type
• Fixed the symmetrization of the inertia tensor for multisphere particles
• Fixed distance checks in region mesh/tet
• Fixed the contact area calculated in the sjkr2 cohesion model
• Fixed the calculation for heat of reaction in fix chem/shrink/core/single
• Fixed coarse-graining factors in scalar transport equation (e.g. used for heat conduction)
• Modified the granular heat conduction model to be in line with Batchelor & O'Brien (1977)

LIGGGHTS-PFM 21.03 release

Notable Changes

• Added reference implementation of the multi-level coarse-grain (MLCG) model of the DEM, including
  • fix ave/euler/region to measure Eulerian properties in a region made up of hex-cells,
  • fix forcecontrol/region that implements a PID controller using data from 2 fix ave/euler/region commands as input,
  • fix massflow/mesh/face to measure mass flow through a surface mesh per cell,
  • fix insert/pack/face to insert particles in a hex-region based on data from fix massflow/mesh/face,
  • region mesh/hex for loading and searching hex-cell regions

(plus their multi-partition counterparts fix ave/euler/region/universe, fix forcecontrol/region/universe, fix massflow/mesh/face/universe, fix insert/pack/face/universe; additionally, some quality of life features have been added, e.g. extract_surface, extrude_surface )

• Added option set_property to fix insert/* to set a value for a property/atom upon insertion (ported from LIGGGHTS-PUBLIC)
• Added option implicit_integration to fix nve/sphere / fix couple/cfd/force/implicit
• Added option ave_euler to dump euler/vtk to specify a certain fix of type ave/euler/* if more than one is used
• Added option cell_center to dump euler/vtk to indicate whether cell centers or complete cell shape should be dumped
• Added option cell_data to fix mesh/surface to load additional cell data from VTK mesh files
• Added option starttime / endtime to fix print

LIGGGHTS-PFM 20.09 release

Notable Changes

• Added C. Richters modifications to granular bond model
• Added flexible bonds modifications by M. Schramm
• Added bonded particle insertion via fix insert/pack
• Added bending and torsional bond stiffness as well as non-linearization of bond interaction force
• Added new cohesion model based on Morse potential
• Added fix meanfreetime to calculate the time between collisions
• Fixed fix chem/shrink/core (multiple particles with different starting conditions, transition from low to high temperature regime)
• Fixed periodic insertion in fix insert/pack/dense
• Fixed region internals not updating upon (sub-)domain change
• Allowed for push and pull vectors of arbitrary length from and to LIGGGHTS

LIGGGHTS-PFM 20.05 release

Notable Changes

• Added a script command to generate a multi-sphere clump file from a surface mesh
• Added support to access DEM variables from CFDEMcoupling
• Added particle deformation model in combination with CFDEMcoupling
• Changed calculation of impact energy for particle breakage

LIGGGHTS-PFM 19.09 release

Notable Changes

• Added support for superquadric particles (ported from LIGGGHTS-PUBLIC) plus paraview plugin
• Added particle chemistry model
• Added paraview plugin for visualizing force chains (by C. Richter)
• Added contact model test cases as described in Chung and Ooi, Granul. Matter 13, 643–656 (2011)
• Fixed bug in dense packing insertion causing particle overlaps
• Fixed compilation with Visual Studio on Windows
• Fixed update of contact history in epsd rolling friction models
• Various bug fixes and minor additions/optimizations

LIGGGHTS-PFM 19.02 release

Notable Changes

• Added code for one2one communication with CFDEMcoupling
• Added fix execute command
• Fixed bug in ycylinder primitive wall
• Fixed bug in fix nve/sphere/limit
• Fixed bug in extracting atom properties

LIGGGHTS-PFM 18.10 release

Notable Changes

• Added new tangential history model using an incremental instead of an integral approach
• Added fix property/atom/polydispparcel
• Added fix couple/cfd/parttempfield
• Modified fix speedcontrol to base the controller on forces instead of velocities
• Modified compute pair/gran/local to optionally compute normal and tangential force components as well as overlap
• Modified fix print to optionally skip writing the title line
• Modified fix insert/pack/dense to use a tighter bounding volume for the initial particle configuration
• Modified the documentation to work with the Sphinx documentation generator
• Fixed bug in fix insert/* when using option insert_every once

LIGGGHTS-PFM 18.03 release

Notable Changes

• Added new primitive wall type general_cone for arbitrarily oriented cones (P. Kieckhefen (TUHH))
• Added documentation for modify_timing and thermo_log commands
• Fixed bug in fix insert/pack/dense in parallel runs
• Fixed bug in fix insert/pack that caused invalid insertion positions